Design the questionnaire in the Portal, set who may see and collect it, then deploy it to the enumerators who will use the app. Deployment is a separate step from design on purpose: it controls who collects data and who can see what comes back.
Video: Quickstart: Creating and deploying your first Survey in mWater on YouTube
The design and deployment split confuses newcomers, and it is the most useful thing to understand early. Design is the questionnaire; deployment is the instance of that questionnaire given to a particular team, with its own permissions and its own data. One survey can be deployed many times, which is how the same national form gets run by different districts without their data mixing.